This application relates to wireless communications.
Wireless communication systems provide voice or data services to subscriber stations or mobile stations (e.g., wireless or mobile stations) situated within a geographic region by dividing the region into a number of cells. Each cell may be further divided into two or more sectors. Each cell contains system communication equipment such as a base station that transmits communication signals to fixed or mobile subscriber stations on the downlink and receives communication signals from the subscriber stations on the uplink. A base station can provide connectivity, management, and control of the subscriber station. One example of wireless communication systems with the above cellular design is wireless networks based on WiMAX (Wireless Interoperability for Microwave Access) technology based on IEEE 802.16 standards, e.g., IEEE 802.16d/e.
In a legacy 3G network, the “Simple IP” network solution supports two types of subscribers, stationary wireless user devices and mobile wireless user devices, over a Radio Access Network (RAN). For both types of subscribers, a packet data session begins when the subscribers wirelessly attach to the Radio Access Network (RAN) and invoke packet data services. A packet data session ends when the user or the network terminates packet data service. During the particular packet data session, the user may change a location anchored to the RAN, i.e., the point of attachment (PoA).
In many existing networks, simple IP user can only obtain an IP address locally. Such usage scenarios include Wi-Fi equipped laptop obtains an IP address from local wireless access point, dial-up user obtains an IP address from local Internet Service Provider (ISP), cable modem/DSL user obtains an IP address locally from its ISP. Common protocols used for IP address configuration in these cases are DHCP or PPP. With the introduction of new technology, such as Proxy Mobile IP (MIP) or Simple IP anchoring at home, the user now has the option to choose whether he wants to have an IP address that is assigned by local network as in the traditional case, or an IP address that is assigned by his home network. When the IP address is assigned by user's home network, the user can invoke additional services or capabilities that are not obtainable by local services only. Such services and capabilities include IP Multimedia Subsystem (IMS), Multicast/Broadcast and IP session continuity during global mobility.